Re: Multiple imports simultaneous?

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Tue, 29 Dec 2015 15:53:28 -0600
Message-ID: <CAJvnOJbXhLd2j5GjTrk2rcJAHceriYtHUY5-C46r=Gz=87RbyA_at_mail.gmail.com>

The method you describe seems overly complex. Why not run 3 different exports simultaneously and then 3 different imports simultaneously? I once wrote a something like that using 6 streams for the export and 6 for the import, and it worked very well. It took some thought to break everything up logically without dependence issues, but once done (it was a process we had to repeat frequently), I just used a shell script to nohup the export processes, and it worked very smoothly.

On Tue, Dec 29, 2015 at 3:45 PM, Storey, Robert (DCSO) < RStorey_at_dcso.nashville.org> wrote:

> In this case it would be part of a LUN in a SAN. But, the new hardware I
> am going to migrate it to (when it gets here) will have 12 disks. I will
> create 6 mirror pairs, and then stripe across the pairs. 2 separate disks
> will hold my redo. So, data and indexes will go onto the raid10 where
> logical volumes will be created just for ease of structure (windows
> environ).
>
>
>
> And my bottleneck has been the table in schema c that has the XMLTYPE as a
> column. That one table seems to take 12 hours, regardless of how I
> approach it. I’m still working on speeding it up, or eliminating it from
> the import.
>
>
>
> *From:* Raza Siddiqui [mailto:raza.siddiqui_at_oracle.com]
> *Sent:* Tuesday, December 29, 2015 3:42 PM
> *To:* Storey, Robert (DCSO)
> *Cc:* Oracle L
> *Subject:* Re: Multiple imports simultaneous?
>
>
>
> Overall # of rows is not huge (in today's terms), or schemas or
> objects...what is more important is mapping of your tablespaces to their
> corresponding files to physical disks - that would be your possible
> bottleneck.
>
> Raza
>
>
> On Dec 29, 2015, at 13:28, "Storey, Robert (DCSO)" <
> RStorey_at_DCSO.nashville.org> wrote:
>
> Just curious about import.
>
>
>
> I’m importing an older 9i system into an 11g system. I am precreating the
> tablespaces, etc.
>
>
>
> Ultimately, the import only cares about 3 schemas. One that only has my
> PL/SQL and the other two have the data. So, Schema A, B, C. Schema B has
> about 360 tables and about 190 million rows total. Schema D has about 45
> tables, but and about 35 million rows of which 27 are in one table that has
> an XMLTYPE column. Importing just the one table in Schema B takes about 12
> hours. I’m working on methods to trim that time.
>
>
>
> But, is it possible to do multiple imports at once if using different
> inbound schemas.
>
>
>
> 1) Export the database to create my dump file.
>
> 2) ON the target server, make 3 copies of the import file.
>
> a. Do an import of Schema A, rows=n, indexes=n, constraints=n
>
> b. Do an import of Schema B, rows=n, indexes=n, constraints=n
>
> c. Do an import of Schema C, rows=n, indexes=n, constraints=n
>
> 3) Do an import for each schema where rows =n, and indexes and
> constraints = y.
>
>
>
> Theoretically, this should not interfere with each other. I can set the
> database to no-archive and increase redo logs so that the waits should be
> reduced.
>
>
>
> Thoughts?
>
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Dec 29 2015 - 22:53:28 CET